[Mesa-dev] [PATCH 12/16] i965/gen7: Use R8_UINT stencil copy when sampling the stencil texture

[Ian Romanick]

On 08/24/2016 04:55 PM, Jordan Justen wrote:
> Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
> ---
>  src/mesa/drivers/dri/i965/brw_wm_surface_state.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
> index 2bafe91..28d0958 100644
> --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
> +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
> @@ -453,8 +453,17 @@ brw_update_texture_surface(struct gl_context *ctx,
>        }
>  
>        if (obj->StencilSampling && firstImage->_BaseFormat == GL_DEPTH_STENCIL) {
> -         assert(brw->gen >= 8);
> -         mt = mt->stencil_mt;
> +         if (brw->gen == 7) {

Any reason to not do gen <= 7?  With all this work in place, it ought to
be trivial for someone to enable this extension on older Gen.

> +            assert(mt->r8stencil_mt && !mt->stencil_mt->r8stencil_needs_update);
> +            mt = mt->r8stencil_mt;
> +         } else {
> +            assert(brw->gen >= 8);
> +            mt = mt->stencil_mt;
> +         }
> +         format = BRW_SURFACEFORMAT_R8_UINT;
> +      } else if (brw->gen == 7 && mt->format == MESA_FORMAT_S_UINT8) {
> +         assert(!mt->r8stencil_needs_update);
> +         mt = mt->r8stencil_mt;
>           format = BRW_SURFACEFORMAT_R8_UINT;
>        }
>  
>